Smoke suppressing device



W. H. SCHWEIZER SMOKE SUPPRESSING DEVICE Filed Sept. .16, 1937 2 Sheets-Sheet l Aug. 6, 1940.

g- 6, 1940- w. H. SCHWEl ZER ,32

SMGKE SUPPRESSING DEVICE Filed Sept. 16, 1937 2 Sheets-Sheet 2 f MQMMW QWA Patented Aug. 6, 1940 UNITED STATES PATENT. OFFICE 8 Claims.

This invention relates to heating devices and more particularly to an improved smoke suppressing device for use in combination with a furnace or boiler so as to prevent the accumula- 8 tion of smoke and soot in the boiler or furnace and in the flue or breeching leading from the heater to the smoke stack.

An object of this invention is to provide in combination with a force feed means in a boiler an auxiliary air feeding means to force a relatively small quantity of air through the heater so as to maintain an even burning of the fuel during the time that the main heat producing means is inactive.

35 Another object of this invention is to provide in a device of this kind means to automatically actuate the auxiliary draft producing device when the main draft producing means is inactive, and to automatically cut oil the auxiliary draft prog) ducing means when the main draft producing means is active.

A further object of this invention is to provide an improved method of producing heat in a boiler orfurnace which is so constructed that the suction from the uptake will not draw out unburned gases which normally produce soot or accumulations in the smoke stack.

A still further object of this invention is to provide means whereby the light dust particles in the furnace or boiler will not be drawn up into the smoke stack and in the flue or breeching during the time that the furnace proper is being cleaned.

A further object of this invention is to provide an attachment in the form of an auxiliary draft 5 producing or air feeding means which may be readily connected to conventional stokers of the mechanical feed type so that when the main stoker is inactive the clean fuel forced into the retort or tuyere will not smolder and thus produce smoke and soot during this inactive period.

With the foregoing and other objects in view, the invention will be more fully described hereinafter, and will be more particularly pointed out in the claims appended hereto.

In the drawings, wherein like symbols refer to like or corresponding parts throughout the several views:

Figure 1 is a perspective view of a heater and stoker having a device constructed according to 50 an embodiment of this invention mounted there- Figure 2 is an end cross section view of the force feed fan and housing taken on line 2--2 of Fig. 3.

55 Figure 3 is a side cross section view of the force feed device air control means and housing taken online33ofFig.2.-

Figure 4 is a diagrammatic view of the electric circuits incorporated with this invention.

Figure 5 is a section taken on the line 5-5 of 6 Fig. 1.

Referring to the drawings, the numeral it designates generally a mechanical stoker which is connected by means of a pipe or flue H to a furnace or boiler i2. The boiler i2 is provided 10 with an outlet or smoke'pipe it which in the present instance has a horizontal portion [4 leading directly to the smoke stack. The stoker i0 is of conventional construction and includes a relatively large fan l5 operated by means of a motor IS. The motor I6 is connected by means of wires ll, l8 and I9 to a source of current supply and the usual thermostatic devices (not shown) and pressure controlling devices connected to the boiler l2 may be interposed in the electric circuit 20 in which the wires l1, l8 and I! are interposed.

The fan l5 includes a housing 20 having an inlet opening 2| in a face thereof through which air is drawn by the fan l5 when the motor I6 is operated. The stoker I0 is preferably associated ,2! with a relatively large boiler l2 and the motor 7 I6 is preferably a relatively large powered motor so as to produce the necessary draft through the flue H to the retort or tuyere positioned within the plenum chamber below the boiler or grate. 30 At the present time, when the stoker I 0 is inactive due to the production of the desired steam pressure or heat, the fuel forced into the retort smolders and produces smoke and it is, therefore, to eliminate this objectionable feature that 86 the hereinafter described auxiliary draft producing means is combined with the stoker II).

A housing 22 is in the present instance secured to the fan housing 20 about the intake opening 2| thereof and this? housing 22 has a front wall 23 provided with an opening 24 which is partially covered by means of an adjustable valve 25. Preferably the air intake opening 24 may be formed as a plurality of radially arranged openings' which may be regulated by means of the rotatable valve 25 mounted on a shaft 26. A pair of valve members 21 and 28 are swingably mounted within the housing 22, the valve. member 21 being mounted on a shaft 29 and the valve member 28 being mounted on a shaft 30. The lower or free end of the valve member or plate 21 is adapted to engage against a flange 3| secured to the bottom wall of the housing 22. A partition or inner wall 32 is secured to an inner horizontal wall 33 disposed in substantially the center of the endis provided with a fiange84' against which the valve member or plate 28 is adapted to engage when in closed position. An upper vertical partition extends downwardly from the top 38 of the housing 22 and coacts with the valve member 28 and the flange 34 in closing the upper portion of the casing 22.

An arm 31 is secured to the valve member or damper 21 and extends downwardly and outwardly thereof. A weight 38 is adjustably secured to the arm 31 and acts to substantially balance the valve member 21 so that a very slight suction will cause the valve member 21 to be drawn to an open position. The valve member 28 also has a forwardly and downwardly inclined arm 38 secured thereto and an adjustable balancing weight 48 is mounted on this arm 38.

In order to eliminate the noise of the closing of the valve members 21 and 28 when the fan I5 is cut off, I have provided check members 4| and 42 which are secured at one end to the housing 22 and at the other end thereof to the valve members or plates 21 and 28, respectively. l'hese check members are constructed in the form of a cylinder having a piston slidable therein with one part secured to the casing 22 and the other part secured to the swingable valve members 21 and 28.

A fan member 43 is secured to the top wall 38 of the casing 22 and is operated by means of a motor 44. The motor 44 is a relatively low powered motor having a conductor 45 connected to a suitable source vof current supply and a second conductor 48 which is connected to an armature 41 of a relay 48. The relay 48 is adapted to be placed in circuit with the main motor I8 so that when the main motor I8 is in operation, the relay 48 will be energiz'ed and the armature 41 will be drawn away from a stationary contact or terminal 48 connected by means of a wire 58 to-a source of current supply. In this manner, when the main motor I8'is inactive, the armature 41 will be drawn by means of a sprlng 5| into contact with the terminal 48 and thus complete the electric circuit to the auxiliary motor 44. If desired, a pressure operated switch member 52 may also be interposed in the electric circuit to the motor 44, this pressure operated switch 52 being interposed in the wire 45 and the pressure member 52 being affected by the temperature or pressure in the boiler or furnace I2. It will be apparent from this that if during. the time the auxiliary fan 43 is in operation, the pressure or heat in the boiler or furnace'I2 becomes excessive, the auxiliary draft member will be automatically cut off.

A plate or valve member 53 is slidably carried by the top wall 38 of the housing 22 and is provided at one end with a knob 54 so that the opening from the fan 43 into the casing 22 may be regulated in ordernot to produce too great a draft to the boiler or furnace I2.

In order to prevent back draft through the fan 43, I have provided a plate 55 which is swingably mounted, as at58, on the underside of the top wall 38 and this plate or valve member 55 is balanced to a normal closed position by means of an adjustable weight 51 mounted on a depending arm 58 carried by the pivoted end of the valve member 55.

A casing 58 is secured to the horizontal flue or duct I4 and is provided with an open outer end 88. A plate or valve member 8| is swingably secured at its upper end to the casing 58 and aarogeae housing 22. The horizontal wall 83' at itsizaner normally engages against a' frame member 82 which is disposed on an inclination to the vertical so that the door or valve 8| will gravitatingly close the opening 88 in the casing 58. A grill 83 may-be placed across the open outer end of the casing 58 so as to prevent paper or other articles from being drawn into the breeching or duct I4. The plate or door 8| has an arm 84 secured to the outer side thereof and a chain or operating member 85 is secured at its upper end to the arm 84 and extends downwardly through an opening 88 in the bottom wall of the casing 58. A handle 81 is secured to the lower end of the chain 85, so that when it is desired to clean the furnace or boiler I2, the damper or valve member 8| may be moved to an open position. The bottom wall 88 of the casing 58 may also be provided with a notch 88 opening into the hole 88 so that the chain 85 may be moved laterally into the notch 81 and thus held against movement so as to keep the valve or door 8| in open position.

A baiiie 18 having a plurality of elongated openings 1| is adjustably secured as by bolts 12 to a side wall 13 of the casing 58. This baflle 18 is relatively smaller in width than the width or diameter of the breeching or flue '|4 so that in any position of the battle 18 across the flue or breeching I4 the gases may pass over the edges of the baflle 18. With the use of this baille 18, the products of combustion are retained for a longer period in the combustion chamber of the boiler or furnace I2 and in this manner, a greater heat exchange will be effected than where the breeching or smoke uptake I4 is not provided with a baille of this type. The adjustment of the baille 18 is made during the time that the stoker I8 is in normal operation so that no undue pressure will be set up in the furnace housing I2.

In the use and operation of this device, the normal running of the furnace I2 is effected by the operation of the motor I 8 and the fan I5. It will be understood that the stoker I8 includes a conveyor in the duct I I to convey the fuel to the retort or tuyere so that a continuous feeding of fuel will be provided. When the desired temperature has been produced by the stoker I8, the conventional controlling devices operatively connected to the motor I8 will cut oil! the current supply through the conductors. I1, I8 and I8 and at this timethe relay 48 will be de-energized so that the spring 5| will be able to swing the armature 41 into circuit closing position with the terminal 48. The motor 44 will then be operated and the air forced into the casing 22 by the fan 43 will swing the valve members 21 and 28 to closed position so that the air from the auxiliary fan 43 will not pass outwardly through the intake.

opening 24 of the casing 22. The air from the fan 43 will enter the casing 22 and then pass through the fan housing 28 into the duct II. The pressure of air from the fan 43 will be substantially less than the pressure produced by the fan I5 so that the fuel in the retort will be burned at a slower rate but at a sufficient rate to prevent smoldering or smoking. 1

The casing 22 with the fan 43 and the motor 44 are here disclosed as being mounted directly on the main fan housing 28, but it will be understood that this auxiliary draft producing means may also be mounted at any desired point along the length of the duct II or at a suitable point in communication with the plenum chamber below the boiler I2. The device herein disclosed has been placed in practical operation and has been found to substantially entirely eliminate thereby eliminate smoldering of fresh fed coal.

the accumulation of dust particles and soot in the boiler or furnace and in addition this attachment effects a considerable economy in the burning of fuel. The device is here disclosed as being combined with a coal stoker but it will be understood that this device and the method of operation may also be combined with other types of burners, such as oil burners or the like.

It is apparent that various changes may be made in this invention, especially in the details of construction, within the scope of claims herewith appended.

What is claimed is:

1. In a smoking suppressing heating assembly, a heater, an electrically operated air feeding means for said heater, an electrically operated auxiliary air feeding means connected to said heater, and means automatically cutting off operatlonof said auxiliary air feeding means during operation of said first air feeding means.

2. In combination with an air feeding means for a heater, 2. housing, means securing said housing to the intake side of said air feeding means, said housing having a relatively large air passage in one wall thereof, suction operated valve members normally closing said air passage, said housing having a second air opening in another wall thereof, and air feeding means connected to said second air opening.

3. An auxiliary air feeding means for a heater, comprising a housing, said housing having a relatively large air passage in one wall thereof,

suction operated valve members normally closing said air passage, means connecting said housing with said heater, said housing having a second air opening in another wall thereof, and air feeding means connected to said second air opening.

4. In combination, a main air feeding means for a heater, including a main blower and electrically operated power means connected to said blower, a relatively small blower operatively connected to said heater, electrically operated power means for said small blower, and a relay operatively connected to each of said power means whereby to render said second power means ineifective during operation of said first power means.

5. In a continuously operating smoke suppressor unit for attachment to a furnace combustion chamber, including a main motor driven fan, a coal feeding conveyor means, an auxiliary motor driven fan and operating. relay means adapted to drive the said main motor driven fan and the said auxiliary motor driven fan alternatively whereby a continuous flow of air is fed through the furnace combustion chamber to 6. In a constantly operating smoke suppressor unit secured to'a furnace combustion chamber,

her is maintained to keep continuous combustion temperature in the furnace combustion chamber;- -'I. A smoke-suppressing, mechanically stoked furnace for burning solid fuel comprising a combustion chamber for said fuel, a mechanical stoker for feeding fuel to said combustion chamber, an electrically operated air feeding means for creating a forced draft in said combustion chamber sufiicient to assure combustion of said solid fuel under predetermined conditions, an

electrical circuit for applying current to said means in accordance with said predetermined conditions, an auxiliary electrically operated air feeding means for creating a forced draft in said combustion chamber only sufficient to prevent smoldering of said solid fuel and to effect combustion of the gases formed in said combustion chamberv during the intervals when said first mentioned air, feeding means is inoperative, a normally open auxiliary electrical circuit for supplying current to said auxiliary air feeding means,

\ and a relay in said first mentioned electrical cir-' cult operative upon cessation of current flow through said first mentioned circuit to close said auxiliary electrical circuit. n

8. Air feeding means for a smoke-suppressing mechanically stoked furnace for burning solid fuel comprising a housing having a relatively large air inlet passage and a substantially smaller air inlet passage, a flue interconnecting the interior of said housing and said furnace for supplying air to said furnace, suction operated valve members normally closing said relatively large air inlet passage; means in said housing for drawing a primary supply of air into said housing and opening said valve members and an electrically operated means on said housing operable alternately with respect to said last mentioned means for forcing an auxiliary supply of air into said housing through said substantially smaller air inlet passage when said valve members are closed, said auxiliary supply of air being only of sufflcient quantity to prevent smoldering of the fuel in said furnace.

WILLIAM H. SCHWEIZER. 

